275's on 8.5" rim?

Would a 275 fit on a 8.5" rim, or would that just look retarded? Just on the back, leaving 245's or 255's on the front.

Pretty sure these are 17x8.5's with 255's on them. I go pick up the car Friday, so I'll know for sure then, but just speculating for now. What do you guys think they are?http://members.***.net/lolol/10i.jpg